1. Field of the Invention
The present invention relates to photosensitive materials which are developed by a wash-off procedure. In particular, the present invention provides photosensitive materials with improved aging stability via incorporation therein of an amine compound or metal-ammine complex.
2. State of the Art
Photosensitive wash-off systems which contain gelatin as the binder in a silver halide emulsion layer, and in any auxiliary layers, produce images when gelatin is tanned or hardened in exposed and developed areas, and untanned or unhardened gelatin is washed off in unexposed areas. Prior art references to such tanning development include U.S. Pat. Nos. 2,596,576, 3,364,024, 3,440,049 and 4,233,392; and British Pat. No. 1,294,355. For this purpose it is essential that the gelatin constituent of the raw film be storage-stable, i.e., resistant to aging reactions which would crosslink or otherwise insolubilize the gelatin during storage, presumably by reactions involving amine sites in the polypeptide linkages of the gelatin chain. Several commercial wash-off films approach this problem by incorporating antioxidants into the gelatin to improve aging stability, but these are only partly effective. Hence, stable high speed wash-off films have not been commercially available. A better means for achieving aging stability is needed.